Drop-out fuse construction



Feb. 16, 1937- A. G. S'TEINMAYER DROP-OUT FUSE CONSTRUCTION Filed Sept. 15, 1934 INVENTOR.

fl/Z/w yJfarm/myar QLM ZA TTORNEY.

Patented F eb. 16, 1937 PATENT OFFICE DROP-OUT FUSE CONSTRUCTION Alwin G. Steinmayer, Milwaukee, Wis., assignor to Line Material Company, South Milwaukee, Wis, a corporation of Delaware Application September 15, 1934, Serial No. 744,175

16 Claims.

This invention relates to a drop out fuse and is particularly directed to a dropout fuse of the expulsion type. i

Objects of this invention are to provide a drop out fuse in which the fuse tube is supported in position and is held in this position by latching means adjacent the lower portion of the tube, such latching means being restrained from releasing motion by the fuse link so that when the fuse link is ruptured the latching means is released and the fuse tube drops downwardly and olutwardly from operative to inoperative posit on.

Further objects are to provide a drop out fuse in which the motion of the parts, upon blowing of the fuse'link, results in the separation of at least one contact carried by the fuse tube from the corresponding stationary contact to thereby greatly increase the gap in the circuit and prevent leakage.

Further objects are to provide a construction of drop out fuse having the characteristics enumerated above, in which the top of the fuse tube is closed to prevent the entrance of rain, in which the upper and lower contacts are of the laminated brush type, and in which one member of the latching means acts as a sleet hood for the lower mechanism and the lower contacts.

Further objects are to provide a construction in which the projecting end of the fuse link is clamped directly to a casting or member carried adjacent the lower member of the fusetube, in which aseparate lever is provided and formsv a portion of the latching mechanism and is controlled by the fuse link, and in which bumpers are provided to arrest the fuse in its lowermost position.

Further objects are to provide a drop out fuse which, though having the characteristics outlined, nevertheless is of simple construction, is composed of relatively few parts, all of which are easy to produce, and which may be easily detached and re-fused and repositioned.

An embodiment of the invention is shown in the accompanying drawinmin which:

Figure Us a side elevation, partly in section, of the device.

Figure 2 is a fragmentary face view of the lower portion of the fuse tube with its associated mechanism.

Referring to the drawing, it will be seen that a fuse tube is indicated by the reference character I. This fuse tube is provided with an upper contact 2 and a lower contact 3. The

upper contact is provided with the usual nut 3' for clamping theupper end of the fuse link 4, the lower end of the fuse link projecting outwardly from the bottom of the fuse tube and being clamped tothe lower contact by means of the thumb nut 5. The upper contact is preferably 5 provided with a manipulating ring 6 adapted to be engaged .by the hook of a switch stick, and the lower contact 3 is preferably provided with an angularly projecting lip I which also may be engaged by a switch stick in repositioning the fuse 10 after re-fusing.

The entire device may be carried by a suitable support 8 which is provided with upper and lower insulators 9 and I0 respectively. The upper insulator carries the upper stationary terminal 15 member which may consist of a conductor receiving or terminal portion Ii and a brush contact l2. Preferably a hood-like member I3 is also carried by the upper terminal member and acts in the manner of a sleet hood for the upper portion of the device. It is provided with a 20 downwardly projecting web it which forms a stop to arrest inward rocking motion of the fuse tube when the fuse tube is being rocked into closed or operative position. It is to be noted that the laminated brush contact l2 bears against 25 the flat inner face of the upper contact 2 of the fuse tube i. If desired, a dead ending ring-like member l5 may be carried by the upper terminal of the device.

The lower terminal member includes a bracket I6 which has a downwardly and inwardly projecting portion l1 and a conductor receiving portion I8, between which the laminated brush contact i9 is clamped. This brush contact I! bears against the flat inner face of the lower contact 3. The bracket member I6 is provided with a bifurcated lower part which is composed of hooklike portions 20 located on opposite sides of the downwardly extending trunnion-carrying part of the member 3, the trunnions being indicated by the reference character 2|. Further, the lower bifurcated portion of the bracket is provided with downwardly projecting feet or arms 22, against which laterally projecting bumpers carried by the member 3 are adapted to strike when the fuse has swung about the trunnion 2| to its lowest position. These bumpers may consist of pins 23 carried by the member 3 and surrounded by rubber or other resilient material 24.

The member 3 carries a pivot pin 25, at which the upper end of a lever 26 is pivoted. The lever 26 is controlled by the fuse link, as shown very clearly in Figure 1, and is held normally in contact with the lower portion of the fuse tube, so

that, when the link is intact, the lever is held as a rigid or immovable member with respect to the fuse tube.

The lever 26 constitutes one portion of the latching means and is provided with a bifurcated upper end terminating 'in' projecting portions or latching noses 21, see Figures 1 and 2. These latching noses are adapted to fit beneath the downwardly turned portions of a phosphorbronze latching member 28, which is provided with shouldered portions, as indicated at 29 in Figure 1, and with upwardly slanting portions 30 beneath which the noses 21 ride during the closing motion of the fuse tube. The phosphorbronze spring member 28 may be relatively wide and may act somewhat as a sleet hood for the lower contact and the lower mechanism, the

projecting portion SE of the lower contact 3 substantially filling out the opening in the spring member 28.

The operation of the device is as follows: When the fuse blows the usual expulsion action takes place and the severing of the fuse link allows the release of the lever 26, permitting such lever to swing outwardly. The lever 26 is urged outwardly due to the pressure of the brush contacts l2 and as, as each of these contacts tends to rotate the fuse tube outwardly about the trunnions 2!. Further, the outward motion of the lever 26 also aids in withdrawing any remaining portion of the fuse link from the fuse tube. It is to be noted further, that the pressure of the spring contacts or brush contacts assists in the :initial motion of the fuse tube.

The fuse tube rocks about the trunnions 2i and swings outwardly and downwardly. The bumpers 24 engage the stops 22 and arrest the rocking motion of the fuse tube.

After the fuse tube has blown, it may be readily re-fused by unhooking the trunnions from the hooked members 2%, as these latter members are open hooked members. If desired, a switch stick of the well known type having means for engaging the lip i may be used to remove the fuse.

The re-fusing is easily done and the re-positioning of the fuse is very easily accomplished by merely hooking the trunnions 2!! into the hooked members 2t, thereafter rocking the fuse into closed positionv the latching member 28 riding upwardly until the portions 2i of the latching lever snap behind the shouldered portion of the latching member 23.

It will be seen that a very simple and reliable type of drop out fuse has been provided which, although having the features hereinbefore enumerated, is composed of a-relatively small number of easily produced and easily assembled parts.

Although this invention has been described in considerable detail, it is to be understood that such description is intended as illustrative rather than limiting, as the invention may be variously embodied and is to be interpreted as claimed.

1 claim:

1. A fuse comprising upper and lower terminal members, a fuse tube having upper and lower contacts electrically connected to said upper and lower terminal members, the lower portion of said fuse tube being directly pivotally supported ing means being restrained from releasing. mo-

tion by said fuse link. said fuse link having its lower free end locked against motion with respect to said fuse tube and remaining locked against motion when said fuse blows.

2. A fuse comprising upper and lower terminal members, a fuse tube having upper and lower contacts electrically connected to said upper and lower terminal members, the lower contact of said fuse tube being pivotally carried by said lower terminal member, said fuse tube having a fuse link, and latching means for directly latchmg the lower portion of said fuse tube to said lower terminal member, said latching means being restrained from releasing motion by said fuse link, said fuse link having its lower free end locked against motion with respect to said fuse tube and remaining locked against motion when ably carried by said fuse tube and normally en- I gaging said catch, said latch being restrained from releasing motion by said fuse link, said fuse link having its lower free end locked against motion with respect to said fuse tube and remaining locked against motion when saidffuse blows.

4. A fuse comprising upper and lower terminal members, a fuse tube pivotally supported from said lower terminal member, a fuse link carried by said fuse tube, a stationary catch carried by said lower terminal member, and a latch lever plvotally carried by said fuse tube and normally engaging said catch, said latch lever being restrained from releasing mbtion by said fuse link and being engaged by an intermediate portion of said fuse link.

5. A. fuse comprising upper and lower terminal members. a fuse assembly pivotally supported from said lower terminal member and having upper and lower contacts and a fuse link el'ectrically connecting said contacts, brush contacts carried by said upper and lower terminal members and normally engaging the contacts of said fuse assembly, and latching means for latching said fuse assembly in operative position, said latching means being carried jointly by said lower terminal member and said fuse assembly and being restrained from releasing motion by said fuse link, that portion of said latching means carried by said lower terminal member being stationary.

6. A fuse comprising upper and lower terminal members, a fuse tube having a lower contact pivotally and electrically connected to said lower terminal member and having an upper contact, a spring contact carried by said upper terminal member and engaging the upper contact of said fuse-tube and urging said fuse tube outwardly, a stationary catch member carried by said lower terminal. member, a latch member carried by said fuse tube and normally engaging said catch member, and a fuse link carried by said fuse tube and normally restraining said latch member from releasing motion. l

7. A fuse comprising upper and lower terminal members, a fuse tube having a lower contact pivotally and electrically connected to said lower terminal member and having an upper contact, a spring contact carried by said upper terminal member and engaging the upper contact of said fuse tube and urging said fuse tube outwardly, a stationary catch member carried by said lower terminal member, a latch lever pivotally carried by the lower contact of said fuse tube and normally engaging said catch member, and a fuse link carried within said fuse tube and projecting from the lower portion thereof and normally restraining said latch lever from releasing.

8. A fuse comprising upper and lower terminal members, a fuse tube having a lower contact pivotally and electrically connected to said lower terminal member and having an upper contact, a spring contact carried by said upper terminal member and engaging the upper contact of said fuse tube and urging said fuse tube outwardly, a stationary catch member carried by said lower terminal member, a latch lever pivotally carried by the lower contact of said fuse tube and normally engaging said catch member, the lower contact of said fuse tube having link fastening means above said latch lever, and a fuse link extending through said fuse tube and outwardly through the bottom of said fuse tube and over said latch lever, the projecting portion of said fuse link being locked to said lower contact by said link fastening means.

9. A fuse comprising an upper terminal member including a sleet hood provided with a stop and a brush contact, a lower terminal member provided with downwardly projecting stops, a fuse tube having an upper contact normally engaged by said brush contact and having a portion in line with the stop of said sleet hood, said fuse tube having a lower contact pivotally supported from said lower member and having bumpers adapted to engage said stops when said fuse swings outwardly to its lowermost position, a latch means carried jointly by said lower terminal member and the lower portion of said fuse tube, and a fuse link electrically joining the contacts of said fuse tube and normally restraining said latch means against releasing motion.

10. A fuse comprising upper and lower terminal members, said upper terminal member having a brush contact, said lower terminal member having hook-like portions and having a pair of laterally spaced stops, a fuse tube having an upper contact bearing against and urged outing a lower contact provided with trunnions detachably held by said hook-like portions, said lower contact having outwardly projecting bumpers adapted to engage said spaced stops when said fuse has swung to its lowermost position, a catch carried by said lower terminal member, a latch lever pivotally carried by the lower contact of said fuse tube and normally engaging said catch member, a fuse link extending from the upper contactof said fuse tube through said fuse tube and outwardly from the lower end thereof and looped over said latch lever, and means adjacent the lower portion of said fuse tube for locking the end of said fuse link, said fuse link normally restraining said latch lever against releasing motion.

11. An automatic fuse switch having a pair of upper and lower terminals provided with contacts, a fuse tube pivoted on the lower terminal and having upper and lower contact blocks electrically engaging said contacts of said terminals, a catch on the lower terminal, a latch member on the lower contact block and engaging said catch, and a fuse link in said tube directly connected to said blocks and holding said latch member against movement, said latch and said catch spaced contacts, a catch connected to one of said.

spaced contacts, a latch member on one of safll blocks and engaging said catch, and a fuse link in said tube directly connecting said blocks and directly engaging said latch member to hold said latch member against movement, said latch and said catch constituting the sole means for holding said fuse tube against outward dropping movement.

13. An automatic fuse switch having a pair of upper and lower terminals provided with resilient contacts, a fuse tube pivoted on the lower terminal and having upper and lower contact blocks electrically engaging said resilient contacts, a catch on the lower terminaLa latch lever pivot-ed on the lower contact block and engaging said catch, and a fuse link in said tube directly connected to said blocks and holding said latch lever against pivotal movement, said latch lever and said catch constituting the sole means for holding said fuse tube against outward dropping movement.

14. An automatic fuse switch having a pair of spaced resilient contacts, .a pivotally mounted fuse tube having spaced contact blocks engaging said resilient contacts, both said resilient contacts urging said fuse tube outwardly, a catch electrically connected to one of said resilient contacts, a latch lever pivoted on one of said contact blocks and engaging said catch, and a fuse link in said tube directly connecting said contact blocks and directly engaging said latch lever to hold it against pivotal movement, said latch lever and said catch constituting the sole means for holding said fuse tube against outward dropping movement.

15. An automatic circuit interrupting switch having an upper and a lower terminal member, an arcing tube having a pivot directly connecting the tube with the lower terminal member, brush contacts carried by the upper and lower terminal members, said arcing tube having spaced contacts normally engaging said brush contacts, a stationary catch carried by said lower terminal member, a latch lever pivotally mounted on said tube and having a catch engaging portion, a flexible expulsible conductor in said tube electrically connecting said spaced contacts, and current controlled means holding said latch lever in engagement with said catch.

16. An automatic circuit interrupting switch having an upper and a lower terminal member, an arcing tube having a pivot directly connecting the tube with the lower terminal member, brush contacts carried by the upper and lower terminal members, said arcing tube having spaced contacts normally engaging said brush contacts, a stationary catch carried by said lower terminal member, a latch lever pivotally mounted on said tube and having a catch engaging portion, a flexible expulsible conductor in said tube electrically connecting said spaced contacts, and current controlled means holding said latch lever in engagement with said catch, the upper brush contact urging said arcing tube outwardly towards inoperative position.

ALWIN G. STEINMAYER. 

